Method and apparatus for the production of crimped yarns

ABSTRACT

The production of crimped yarns in which at least two yarns are fed under tension to a common twisting zone, wherein the yarns are pretwisted together and heated so as to be under a plastic state at least in a part of the zone. The yarns are thereafter separated into individual yarns by being pulled apart in different directions and at the same speed. The twisted yarns are turned at the separating point in the same direction as that of the initial pretwisting while the separated yarns are also turned in the same direction as that of the initial pretwisting.

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[151 maaalm 1 1Feh.22, 11972 [54] METHUD AND APPARATUfi WUHR THEPRUDUCTHUN UP 'CiltllF/llPlElIl YARNE S [72] Inventors: Yutallm Malaria,Fujiyoshida-shi; lllirosliiro Mimura; Altio lltoshimo, both of Uji-shi;

Nagamasa lllki, liyoto-fu; llfiatsumi Yasuzuira; Yoshinohu Furultawa,both of Ujishi, all of Japan Nippon ll iayon Company Limited, Uji-shi,

Japan 1221 Filed: liept. 2t), W11 i) |21| Appl. No.1 9561,3119

I73] Assignee:

[30] Foreign Application Priority Data June 18, 1969 Japan ..44/56831[52] 1.1.8. (11. 057/3 1 HS, 57/77.4, 57/157 T8 [51] llnt. Cl ..1D02g11/02 [58] Field 011 Search ..57/34 NS, 77.3, 77.4, 77.42, 57/1 7 5,. .7M 1575134 B.

[56] References tlited UNITED STATES PATENTS 2,111,211 3/1938 Finlaysonet al. ..57/77.3 X

Gilchrist et a1. ..57/157 Berger, Jr. ..57/34 Primary Examiner-StanleyN. Gllrea th Assistant Examiner-Wemer H. Schroeder At!0rneyPicrce,Scheffler & Parker 57 scr The production of crimped yarns in which atleast two yarns are fed under tension to a common twisting zone, whereinthe yarns are pretwisted together and heated so as to be under a plasticstate at least in a part of the zone. The yarns are thereafter separatedinto individual yarns by being pulled apart in different directions andat. the same speed. The twisted yarns are turned at the separating pointin the same direction as that of the initial pretwisting while theseparated yarns are also turned in the same direction as that of theinitial pretwisting.

11 Claims, 10 Drawing Figures PAIENIEmmzz I972 SHEET 5 [IF 5 METHOD ANDAPPARATUS FOII TlllllE FIKOD UCTIION OF ElltIlVllFlEllI ifAIthlSBACKGROUND OF THE INVENTION This invention relates to a method andapparatus for the production of crimped yarns.

As herein used, the term crimped yarns refers to yarns consisting of oneor more endless filaments or fibers. The yam material of such yarnincludes at least in part of synthetic thermoplastic materialsespecially polyamide, polyethylene terephthalate, polyacrylonitrile,polyolefine, and the like.

Apparatus and process for the crimping of textile yarns are knownaccording to which at least two yarns are twisted together in a twistingzone while being subjected to heating so as to be under a plastic stateat least in a part of the zone, and are then separated into individualyarns by being pulled apart in different directions and at the samespeed.

When yarn is treated in this way, it has been observed that certainforces are often set up which overstress the yarn and cause it to break.

Still further it has been found that such disadvantageous forces are setup when the separating point fluctuates to and fro along the yarnrunning direction whereas the forces are not set up when the separatingpoint is maintained constant during the operation. Such fluctuation willprevent a common twisting zone from maintaining a constant lengththereof. This, in turn, prevents the yarns from being crimped uniformly.

OBJECT OF THE INVENTION The object of the present invention is toprovide a method and an apparatus referred to at the beginning of whichthe breakage of the yarns during the operation can be avoided.

Another object of the present invention is to provide a method andapparatus of which the separating point is maintained constant duringthe operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an elevational view of anembodiment of the apparatus according to the present invention in whichboth the feeding zone and initial twisting zone are not shown,

FIG. 2 is a side view of the apparatus shown in FIG. I, in which thedrawoff roller is not shown,

FIG. 3 is a plan view of the stationary yarn guide employed in theapparatus shown in FIG. I,

FIG. l is a schematic representation of one form of the feeding zone andthe twisting zone according to the present inventlon,

FIG. 5 is an elevational view of another embodiment of the apparatusaccording to the present invention, in which both the feeding zone andtwisting zone are not shown,

FIG. 6 is a side view of the apparatus of FIG. 5,

FIG. 7 is an elevational view of a further embodiment of the apparatusaccording to the present invention in which both the feeding zone andtwisting zone are not shown,

FIG. 8 is a side view of the apparatus shown in FIG. 7.

FIG. 9 is an elevational view of a still further embodiment of theapparatus according to the present invention in which the feeding zoneand twisting zone are not shown.

FIG. III is a side view of the apparatus as shown in FIG. 9.

DETAILED DESCRIPTION OF THE METHOD AND APPARATUS The present method forsolving the aforementioned problems is characterized mainly in that atleast two yarns pretwisted together are turned at the separating pointin the same direction as that of the initial pretwisting and then eachof the separated yarns is turned in the same direction. Yarns pretwistedtogether in an S-direction should be turned at the separating point in acounterclockwise direction when viewed along the yarn running directionand then each of individual yarns separated therefrom should be turnedin the same direction, whereas, yarns pretwisted together in aZ-direction LII should be turned at the separating point in a clockwisedirection when viewed along the yarn running direction and then each ofindividual yarns separated therefrom should be turned in the samedirection.

In a heretofore known method, for example, it has been ob served thatthe separating point is apt to fluctuate longitudinally as the yarnsrun. In synchronism with the fluctuation, certain forces are set upwhich overstress the yarns and cause the breakage of the yarns. Thepresent invention therefore is directed to maintaining the separatingpoint constant during the operation by turning both the twisted yarnsand the separated yarns, i.e., by preventing the separating point fromshifting toward the drawoff roller as the yarns run.

It has been observed in the known art that the crimped yarn has a torquewhich would cause the yarn to produce snarls along its length when theyarn is in a relaxed state and the yarn is likely to break when the yarnis retensioned. It is our belief that the turning at two points willcause the yarns to lose temporarily the disadvantageous torque betweensaid two points.

A rotatable hollow spindle is found preferable for the purpose ofturning the yarns, wherein the yarn is wrapped around a snubbing bar andpassed through the hollow spindle.

A moving friction means is also found preferable for turning the yarn.In case such moving friction. means is used, the yarn can be treatedunder constant tension by a frictional force occurring between thesurface of the moving friction means and the yarn running in frictionalcontact with the surface of the friction means. It is preferable thatthe surface of the moving friction means be made of a elastic materialhaving a suitable hardness, for example, a shore hardness of from to 90,such as natural rubber, polyurethane, polybutadiene, polychloroprene,nitrilbutyl and the like, each of which should have good anti-abrasionproperties.

In the present invention, yarns may be heated in the twisting zoneand/or in the feeding zone so as to be in a plastic state at least in apart of the twisting zone.

As another important object of the present invention, we provide anapparatus in which at least two yarns are fed to a twisting zone, arepretwisted together, are heated so as to be in a plastic state at leastin a part of the twisting zone, and are thereafter separated intoindividual yarns by being pulled apart in different directions and atthe same speed, the improvement comprising a yarn turning means forturning the yarns pretwisted together in the same direction as that ofthe initial pretwisting and turning individual yarns after beingseparated in the same direction as that of the initial pretwistmg.

At least three rotatable hollow spindles may be used as a yarn turningmeans.

Also at least two moving friction means, such as, rotating discs, movingendless belts, and the like, may be used as a yarn turning means.

Still further, a rotatable ring may be advantageously used as the yarnturning means. The term ring herein used is to be understood asincluding a doughnut-shaped ring, a short tube, a disc having a hole atits center, and the like. The yarns pretwisted together are brought incontact with one side surface of the ring, are separated into individualyarns, and the individual separated yarns thereafter are brought incontact with opposite side surfaces of the ring, whereby the yarnstwisted together are turned in the same direction as that of the initialpretwisting and the individual yarns are turned in the same direction asthat of the initial pretwisting.

Referring now to drawings, one embodiment of the present invention isillustrated in FIGS. I to 3, in which a rotatable ring is provided as ayarn turning means. In FIGS. I and 2, both the feeding zone and thetwisting zone are not shown and only an end section of a pretwisted yarnl is shown. Yarns 2 and 3 to be crimped are fed by feeding means definedby pairs of rollers A and 5 (see FIG. 4) with a constant speed overfreely rotatable guide rollers 6a and 6b, to a twisting zone in whichthe yarns between points 9 and I0 (FIG. I and I) are twisted togetherand heated by heating appliance 6 for the purpose of heat setting thefalse twist thus produced. As will be seen from FIG. 2, the end sectionof the twisted yarn 1 runs over the front side surface and then throughthe center hole of the ring 15 to the back side surface in frictionalcontact with these surfaces along a selected length of the yarns, sothat the twisted yarn 1 and separated yarns 2 and 3 are turned by beingbrought into contact with the rotatable ring 15, for a purpose to bemade clear. Yarns 2 and 3 divergently separated at separating point areguided through a small hole 21 provided at the end of stationary yarnguide 14 (FIG. 3), the location of which is usually selectedsubstantially on the center axis of the ring. The separated yarns runthereafter to drawoff rollers 11 and 12 over freely rotatable guiderollers 7 and 8. It is noted that the ring 15 should be rotated in acounterclockwise direction when viewed from the front side of the ringin the instance where the pretwisted yarn has S-twist, whereas clockwiserotation should be applied to the ring in the instance where thepretwisted yarn has Z-twist as shown in FIG. 1. The ring 15 is rotatablysupported by a stationary ring 16 having ball bearings 20. The core ofthe ring 15 is made of a magnetizable material and the surface of thering is made of rubber. In parallel, coaxial, and spaced relation withthe ring 15, there is provided a magnetic disc 19 (FIGZ mounted on adriven shaft 18, so that the ring may be rotated by a magnetic force ofthe magnetic disc.

Stationary yarn guide 14 is arranged so as to face the front side of thering 15, and is screwed to an end of rod 17. The stationary yarn guidehas a small hole 21 in a manner such that the hole is locatedsubstantially at the center of the ring 15.

Another embodiment illustrated in FIG. 5 and 6 differs from theabove-described embodiment by the fact that the ring 15, yarn turningmeans, is replaced by two rotating discs 22 and 23 mounted on a drivenshaft 24. The end section of the pretwisted yarn l is brought intocontact with the disc 22 and the separated yarns 2 and 3 are broughtinto contact with the disc 23. The separated yarns 2 and 3 run throughhole 21 of the stationary yarn guide 14 to the drawoff rollers 11 and12. In case the pretwisted yarn 1 has an S-twist, the discs 22 and 23should be rotated in a clockwise direction when viewed along the yarnrunning direction, whereas in the case where the twisted yarn has aZ-twist the discs rotate in a counterclockwise direction. At least thesurfaces of the discs 22 and 23 are made of rubber for providing africtional surface which is effective to rotate the running yarn.

Still another embodiment illustrated in FIG. 7 and 8 differs from theaforementioned embodiments by the fact that the ring or discs arereplaced by three rotatable hollow spindles all of which have similarsnubbing bars at their top. The end section of the pretwisted yarn 1passes through the first hollow spindle 25, being wrapped around the bar26 for the purpose of being turned as the spindle rotates. Having beenseparated at the separating point 10 a short distance after the bar 26,the yarns 2 and 3 then run respectively through the second hollowspindles 27a and 27b after passing through the hole 21 of the stationaryyarn guide 14, and over the freely rotatable guide rollers 7' and 8. Theyarns 2 and 3 after passing through the spindles 27a and 27b and, beingwrapped around the snubbing bars 28a and 28b respectively for thepurpose similar to the twisted yarn are finally run to the drawoffrollers 11 and 12. All of the spindles 25, 27a, and 27b should berotated in the same directions depending upon the twist direction of thetwisted yarn.

According to the embodiment shown in FIGS. 9 and 10, the operation issimilar to that shown in FIGS. 5 and 6 but includes two endless belts 29and 30 spaced apart but parallel to each other which are used instead ofthe ring, discs or hollow spindles of the other embodiments. Thepretwisted and heatset ply yarn 1 passes over the first upper endlessbelt 29 driven by pulleys 31 and 31' frictionally engaging therewith.The ply yarn then passes through an eye or guide 21 formed at the end ofbar 14 mounted on a fixed part of the apparatus. The ply yarn, which inthis instance is formed of two yarns, is divided or separated into twoyarns 2 and 3 at a position just slightly prior to the eye 21.

The two yarns 2 and 3, now crimped, then pass respectively over thesecond endless belt 30 driven by pulleys 32 and 32 frictionally engagingtherewith and thence over guide rollers 7 and 8 mounted on a fixed partof the apparatus.

The yarns then pass two pairs of feed or drawoff rollers 11 and 12respectively and thence to the takeup bobbins not shown.

It will be readily found that the ring 15 of FIG. 1 may be provided witha gear concentric to the ring for driving the ring in mesh with anydriving gear in a manner that will be apparent to those skilled in theart.

Still further it will be found that one or more hollow spindles may beused in combination with one or more moving friction means hereinabovementioned in such a manner that for example the pretwisted yarn may passthrough a hollow spindle and the separated yarns thereafter pass by theturning disc in frictional contact with peripheral edge of the disc.

From the foregoing description, it will be seen that we have conceived amethod and apparatus useful in the crimping of the textile yarns bywhich we are able to separate two or more twisted yarns into individualyarns without breakage, and to maintain the separating point constant sothat the length of the twisting zone can be maintained constant andyarns having uniform crimp characteristics can be effected at highspeed. For example, the yarn can be treated at the speed of from 400 to1,200 meters per minute by the use of the method of the presentinvention.

This invention is not to be confined to any strict conformity to theshowing in the drawings but changes or modifications may be made thereinso long as such changes or modifications mark no material departure fromthe spirit and scope of the appended claims.

1. A method for producing crimped yams composed at least in part ofsynthetic thermoplastic materials which comprises:

pretwisting at least two yarns into a multiply yarn,

heating the multiply yarn to render it partially plastic, turning themultiply yarn in the same direction as when pretwisting the at least twoyarns,

separating the multiply yarn into the individual yarns at a separatingpoint by drawing the individual yarns apart in different directions atthe same speed, and

turning the individual separated yarns in the same direction as that ofthe initial pretwisting to form the multiply yarn.

2. A method as claimed in claim 1 wherein the said at least two yarnstravel at a speed of from about 400 to 1,200 meters per minute.

3. Apparatus for producing crimped yarn composed at least in part ofsynthetic thermoplastic materials comprising,

means for pretwisting at least two yarns to form a multiply yarn,

means for heating the multiply yarn to render it partially plastic,

a first turning means for turning the multiply yarn in the samedirection as that of the initial pretwist of the at least two yarns toform the multiply yarn,

means for drawing each individual yarn of the multiply yarn in differentdirections at the same speed, whereby the multiply yarn is separatedinto the individual yarns at a separation point,

second turning means for turning each of the separated yarns in the samedirection as that of the initial pretwist of the at least two yarns toform the multiply yarn, said second turning means being located betweenthe point of separation and the drawing means.

4. Apparatus as claimed in claim 3 wherein said first turning meanscomprises a rotatable hollow spindle provided with a snubbing bar acrossthe axis thereof, the multiply yarn passing over said bar in windingrelation therewith while passing through the hollow spindle so that theyarn is turned.

5. Apparatus as claimed in claim 3 wherein said first turning meansincludes a moving means having a friction surface which engages themultiply yarn so as to turn the multiply yarn.

6. Apparatus as claimed in claim wherein the friction surface iscomposed of a material selected from the group consisting of naturalrubber, polyurethane, polybutadiene, polychloroprene, nitrilbutyl andmixtures thereof.

'7. Apparatus as claimed in claim 5 wherein the friction surface has ashore hardness of from about 70 to about 90.

8. Apparatus as claimed in claim 5 wherein said moving means comprises amoving endless belt having a friction surface.

9. Apparatus as claimed in claim 3 wherein said second turning meanscomprises at least two hollow spindles each including a snubbing baracross the axis thereof, the separated yarn passing over said bars inwinding relation therewith while passing through the hollow spindle sothat the separate yarns are turned.

Ml. Apparatus as claimed in claim 3 wherein said second turning meansincludes moving means having a friction surface which engages each ofthe separated yarns.

llll. Apparatus as claimed in claim 3 wherein said first turning meansand said second turning means comprise a single rotatable annular ring,diametrically opposed surfaces thereof forming said first and secondturning means respectively.

1. A method for producing crimped yarns composed at least in part ofsynthetic thermoplastic materials which comprises: pretwisting at leasttwo yarns into a multiply yarn, heating the multiply yarn to render itpartially plastic, turning the multiply yarn in the same direction aswhen pretwisting the at least two yarns, separating the multiply yarninto thE individual yarns at a separating point by drawing theindividual yarns apart in different directions at the same speed, andturning the individual separated yarns in the same direction as that ofthe initial pretwisting to form the multiply yarn.
 2. A method asclaimed in claim 1 wherein the said at least two yarns travel at a speedof from about 400 to 1,200 meters per minute.
 3. Apparatus for producingcrimped yarn composed at least in part of synthetic thermoplasticmaterials comprising, means for pretwisting at least two yarns to form amultiply yarn, means for heating the multiply yarn to render itpartially plastic, a first turning means for turning the multiply yarnin the same direction as that of the initial pretwist of the at leasttwo yarns to form the multiply yarn, means for drawing each individualyarn of the multiply yarn in different directions at the same speed,whereby the multiply yarn is separated into the individual yarns at aseparation point, second turning means for turning each of the separatedyarns in the same direction as that of the initial pretwist of the atleast two yarns to form the multiply yarn, said second turning meansbeing located between the point of separation and the drawing means. 4.Apparatus as claimed in claim 3 wherein said first turning meanscomprises a rotatable hollow spindle provided with a snubbing bar acrossthe axis thereof, the multiply yarn passing over said bar in windingrelation therewith while passing through the hollow spindle so that theyarn is turned.
 5. Apparatus as claimed in claim 3 wherein said firstturning means includes a moving means having a friction surface whichengages the multiply yarn so as to turn the multiply yarn.
 6. Apparatusas claimed in claim 5 wherein the friction surface is composed of amaterial selected from the group consisting of natural rubber,polyurethane, polybutadiene, polychloroprene, nitrilbutyl and mixturesthereof.
 7. Apparatus as claimed in claim 5 wherein the friction surfacehas a shore hardness of from about 70 to about
 90. 8. Apparatus asclaimed in claim 5 wherein said moving means comprises a moving endlessbelt having a friction surface.
 9. Apparatus as claimed in claim 3wherein said second turning means comprises at least two hollow spindleseach including a snubbing bar across the axis thereof, the separatedyarn passing over said bars in winding relation therewith while passingthrough the hollow spindle so that the separate yarns are turned. 10.Apparatus as claimed in claim 3 wherein said second turning meansincludes moving means having a friction surface which engages each ofthe separated yarns.
 11. Apparatus as claimed in claim 3 wherein saidfirst turning means and said second turning means comprise a singlerotatable annular ring, diametrically opposed surfaces thereof formingsaid first and second turning means respectively.